Electricity generation

Electricity generation is the process of creating electric power from sources of primary energy. For utilities in the electric power industry, it is the first step before electricity is sent to homes and businesses through transmission and distribution networks. Since electricity cannot be found freely in nature, it must be produced by changing other forms of energy into electricity.

Production happens in power stations, also known as power plants. Most often, electricity is made at a power plant using electromechanical generators. These generators are usually powered by heat engines that burn fuels like coal or gas, or by nuclear fission. Other ways to create electricity include using the kinetic energy of flowing water and wind, as well as solar photovoltaics and geothermal power.

As the world works to limit climate change, there is a push to phase out coal-fired and gas-fired power stations or capture their greenhouse gas emissions. Solar power and wind power are expected to become much more important as electricity demand grows with the electrification of transport, homes, and industry. In 2023, it was reported that the global electricity supply was getting closer to peak CO₂ emissions because of the increasing use of solar and wind power.

History

The basic ideas behind creating electricity were discovered in the 1820s by a scientist named Michael Faraday. He showed that moving a wire near a magnet could produce electricity, a method we still use today. The first big change came when scientists learned how to send electricity over long distances using something called alternating current.

The first central power station began operating in 1882 in New York, using a steam engine to create electricity for street lights. From there, more and more cities started using electricity. Over time, people found many ways to make electricity, including using water, coal, wind, and the sun. As electricity became a part of everyday life, more homes and businesses started using it, leading to the creation of the power grids we rely on today.

Methods of generation

Electricity can be made from many different sources. The most common ways include using machines called electric generators that spin to create power, and special panels called solar cells that turn sunlight directly into electricity. Other methods include using chemicals in batteries and even special materials that create power from movement or heat.

The world uses many sources to make electricity. Coal and natural gas are still widely used, but renewable sources like wind and solar are growing fast. Each method has its own advantages and helps provide the power we use every day.

Main article: Electric generator

Economics

See also: Cost of electricity by source and Electricity pricing

Different ways of making electricity work better for people depending on where you live and how much power is needed. Some places use water flowing downhill, others use heat from coal or natural gas, and some use special plants that use very little space but cost a lot to build.

Every day, power grids need a certain amount of electricity, called the base load, which is the smallest amount of power needed. Some plants, like those using water or special fuels, can provide this steady amount of power all the time.

Generating equipment

Main article: Electric generator

Electric generators have been around since the 1830s when scientists discovered electromagnetic induction. Generally, a generator works by using a prime mover, like an engine or turbine, to spin a magnetic field near coils of wire, turning mechanical energy into electricity. Most electricity today comes from turbines, which are driven by wind, water, steam, or burning gas. These turbines power generators to produce electricity.

The main ways to create this mechanical energy include using heat engines, hydro power, wind, and tidal power. Fossil fuels supply most energy for heat engines, with nuclear fission and renewable sources also contributing. Steam turbines, invented in 1884, produce about 80% of the world's electricity using various heat sources. Other methods include using water movement in hydroelectric plants, wind turbines, and newer technologies like supercritical carbon dioxide cycles, which promise even better efficiency. Smaller generators can also use gasoline or diesel engines for backup power or in remote areas.

World production

Total world electricity generation in 2024 was 30,850 terawatt-hours. This electricity came from many different sources. Coal provided the largest share at 34%, followed by gas at 22%. Other important sources included hydroelectric power at 14%, nuclear power at 9%, wind at 8%, and solar at 7%. Smaller amounts came from oil and other fossil fuels, as well as biomass.

Main article: List of countries by electricity production

See also: Electric energy consumption

Environmental concerns

Main article: Environmental impact of electricity generation

See also: Global warming and Coal phase out

The way electricity is made can affect the environment differently in various countries. For example, in France only a small amount of electricity comes from fossil fuels, while in the United States and China a much larger share does. Electricity made from burning fossil fuels releases gases that warm the planet and can harm the environment.

Experts believe that by 2040, most electricity should come from cleaner sources to help protect the Earth. Some suggest using more nuclear and renewable energy. While nuclear power doesn’t release gases that warm the planet, it does have other risks that need careful management. Overall, making electricity from coal and gas creates much more pollution compared to other methods.

Centralised and distributed generation

Centralised generation refers to producing electricity in large facilities, often far from where people use it. These power plants usually burn fossil fuels like coal or natural gas, but they can also use nuclear power or large hydroelectric dams. The electricity travels through transmission lines to reach homes and businesses.

Distributed generation, on the other hand, creates electricity on a smaller scale, closer to where it is needed. This can include using solar panels on rooftops or wind turbines. Recently, more people have started using distributed generation because it often relies on renewable energy sources like rooftop solar.

Technologies

Centralised energy sources come from large power plants that make lots of electricity for many people. Most of these plants are thermal power plants, using fuels like coal, gas, or nuclear power to heat water into steam. The steam spins a turbine to create electricity. Today, solar and wind power are also used on a large scale.

Hydroelectricity comes from the power of moving water. It supplies a big part of the world’s electricity and can quickly adjust to meet demand. Natural gas plants burn gas to spin turbines, but they still add to climate change. Nuclear power plants use the energy from splitting atoms, called nuclear fission, to create heat that makes steam and spins turbines to generate electricity. While nuclear power has benefits, accidents in the past have raised concerns about safety.

Electricity generation capacity by country

Main article: List of countries by electricity production

The table shows 45 countries and their total electricity capacities from 2022. According to the Energy Information Administration, the world's total electricity capacity in 2022 was nearly 8.9 terawatt (TW), which is more than four times what it was in 1981. On average, each person in the world had access to about 1,120 watts of electricity capacity in 2022.

Iceland leads with the highest electricity capacity per person, at around 8,990 watts. Most developed countries have more electricity capacity per person than the global average, with the United Kingdom having the lowest among developed nations.